The present invention relates to an apparatus and a method for deciding whether a bump formed on either one of an electronic component and a circuit board is joined good to an electrode portion of the other, for example, when the bump formed on an electrode of the electronic component is connected to an electrode part on the circuit board to manufacture a semiconductor component, and an apparatus with the bump joining determination apparatus and a method for manufacturing semiconductor components.
In order for electrically connecting and fixing an electronic component onto a circuit board, there is a method whereby bumps formed on either one of the electronic component and the circuit board are joined to electrode portions of the other. The description hereinafter will be directed to a method of joining the bumps formed on electrodes of the electronic component to electrode parts on the circuit board. An apparatus which executes the bump join method is, e.g., a semiconductor component manufacturing apparatus 1 shown in FIG. 30. The semiconductor component manufacturing apparatus 1 roughly comprises a component feed apparatus 2, a bonding stage 3, a component reverse apparatus 4, a bump join apparatus 5, and a circuit board transfer apparatus 6.
The component feed apparatus 2 is an apparatus for feeding semiconductor chips as an example of the aforementioned electronic component. The circuit board transfer apparatus 6 carries a circuit board 20 in and out of the semiconductor component manufacturing apparatus 1. The bonding stage 3 is a stage for loading the circuit board 20 carried in by the circuit board transfer apparatus 6 for the bump joining, which can be moved in a Y-direction by a Y-axis robot 7 and heats the circuit board 20 for the bump joining. The component reverse apparatus 4 holds the semiconductor chip from the component feed apparatus 2 and turns the held semiconductor chip upside down so that bumps formed on electrodes 13 of the semiconductor chip face the circuit board 20 placed on the bonding stage 3. The bump join apparatus 5 includes a holding device for holding the semiconductor chip, a Z-direction driving device 51 for moving the held semiconductor chip in a thickness-direction, and an ultrasonic vibration generating device 9 which will be detailed later. The bump join apparatus 5 is mounted to an X-axis robot 8 and can be moved in an X-direction by the X-axis robot 8. After receiving the semiconductor chip from the component reverse apparatus 4 and transferring it to the bonding stage 3, the bump join apparatus 5 presses the held semiconductor chip by driving the Z-direction driving device 5 to a predetermined position of the circuit board 20 placed on the bonding stage 3, thereby joining the bumps. The bump, before being pressed to an electrode part 21 of the circuit board 20, keeps a shape as shown in FIG. 32, having a diameter I of approximately 100 xcexcm, a height III at a base part 11a on the electrode 13 of the semiconductor chip 150 of approximately 30-35 xcexcm, and a total height II of approximately 70-75 xcexcm. The pressed bump after being crushed (the pressed bump 11 will be denoted by a reference numeral xe2x80x9c12xe2x80x9d hereinbelow) is shaped as illustrated in FIG. 33. A height IV of the pressed bump 12 is approximately equal to the height III of the base part 11a. 
The semiconductor chip to be joined onto the circuit board 20 is located by the X-axis robot 8 and Y-axis robot 7.
The bump join apparatus 5 is equipped with the ultrasonic vibration generating device 9 for vibrating the bumps 11 in the Y-direction or X-direction thereby generating a frictional heat between the bumps 11 and the electrode parts 21 of the circuit board 20, and reducing a heating temperature of the bonding stage 3 to tightly unite the bumps 11. The ultrasonic vibration generating device 9 has, as shown in FIG. 31, piezoelectric elements 91 and an ultrasonic horn 92 having one end part connected to the piezoelectric element 91. Ultrasonic vibration is generated when a voltage is placed to the plurality of the layered piezoelectric elements 91. The generated vibration, for instance, in the Y-direction is amplified by the ultrasonic horn 92. A nozzle 93 for holding the semiconductor chip 150 is fixed to the other end part of the ultrasonic horn 92. The above vibration of the piezoelectric elements 91 vibrates the nozzle 93, namely, semiconductor chip 150 held by the nozzle 93 in the Y-direction. Although the piezoelectric elements 91 vibrate, e.g., in the Y-direction, vibrations in various directions are generated in a process while the generated vibration being transmitted to the semiconductor chip 150. Therefore, the semiconductor chip 150 vibrates actually in various directions although it primarily vibrates in the Y-direction.
In the above-described conventional semiconductor component manufacturing apparatus 1, after the bumps 11 of the electronic component are pressed to the circuit board 20 heated to approximately 150xc2x0 C. on the bonding stage 3, the bumps 11 are ultrasonically vibrated via the electronic component, whereby the frictional heat is generated between the bumps 11 and electrode parts 21 to join the bumps and electrode parts.
Joining the bumps 11 and electrode parts 21 in this manner allowed portable telephones and personal computers to be made more compact and light-weight. However, whether the joining is good or not was not determined during the joining process in the conventional method. The joining at narrow-pitch electrodes requires a mounting equipment with high accuracy. Further, parts failing in the joining process could not be corrected and products containing such failure must be dumped.
According to the xe2x80x9cmounting apparatus for flip chip componentsxe2x80x9d described in the published specification of JP, 07-142545, A, as a prior art, the mounting apparatus was carried out using a method in which a state of bumps and a joining state thereof were confirmed by an infrared image pickup means before and after a flip chip IC was mounted, so that defective components were eliminated and only good components were sent to a next process. According to the prior mounting method, the flip chip IC sucked by a nozzle with a heater was moved and mounted to a predetermined position on the printed board. Immediately following this operation, picking up was performed by the infrared camera from below. Only joined parts of the circuit board were extracted from image data, and a positional deviation and join area of the joined parts were calculated and then compared with a preliminarily set allowance. A mount state was determined accordingly in the method.
On the other hand, in the xe2x80x9cmounting apparatus for flip chip componentsxe2x80x9d disclosed in the published specification of JP, 10-075096, A, a quantity and a shape of a conductive adhesive at the bump or a top part of the bump were measured with use of a CCD camera immediately before the flip chip IC was joined to a printed board, thereby deciding whether or not a state of the electrode was good. Only good components were hence joined to the printed board.
In the conventional techniques as above, that is, in the method of extracting the electrode shape of bumps of IC chip or the like with use of the infrared camera or CCD camera and processing images, the join state was able to be determined solely from an appearance such as the shape, area or the like of electrodes. Thus, there was a problem whether or not the bumps and electrode portions were truly joined was not correctly determined through visual inspection on the shape, area or the like.
Moreover, even if it was possible to tell failures by the shape, the failures could not be corrected with manipulation added. As a result, there was a problem that an improvement in yield could not be enhanced.
The present invention is devised to solve the above-described problems and has for its object to provide an apparatus and a method for deciding whether or not bumps formed to either one of an electronic component and a circuit board are joined good to electrode portions of the other during the joining process and moreover, a condition of the joining is changed in the case where a failure is estimated to take place, and to provide an apparatus with the bump joining determination apparatus and a method for manufacturing semiconductor components.
In order to achieve the aforementioned objective, according to a bump joining determination apparatus as a first aspect of the present invention, there is provided a bump joining determination apparatus for deciding a good or defective of bump joining at a time when electrodes of an electronic component and electrode parts of a circuit board are joined via bumps with the electronic component and the circuit board relatively vibrated so as to manufacture a semiconductor component, the apparatus comprising a vibration damping detect device for detecting damping of the vibration incident to progress of the joining, and a deciding device for deciding whether the joining is good or defective on a basis of the vibration damping detected by the vibration damping detect device.
In the bump joining determination apparatus in the first aspect, the vibration damping detect device may detect an impedance value of a vibration generating device increasing in accordance with the vibration damping with the electronic component and the circuit board relatively vibrated, and the deciding device may determine whether the joining is good or defective on a basis of an increase tendency of the impedance value resulting from the vibration damping.
The above deciding device can be constituted to determine that the joining is good when the impedance value increases in accordance with a lapse of time after a start time of applying the vibration, reaches a balanced value after a necessary join time has passed since the start time, and maintains the balanced value for a stable time after the necessary join time.
The relative vibration to the electronic component and circuit board may be provided by vibrating the electronic component while the circuit board is fixed.
In the above bump joining determination apparatus, the vibration damping detect device may have a width measuring device for measuring a vibration width of the vibration with utilization of a laser light, and the deciding device determines whether the joining is good or defective on the basis of damping in vibration width.
The width measuring device may irradiate the laser light at a right angle to a vibration measurement face and may measure the vibration width on the basis of reflecting light when the relative vibration to the electronic component and circuit board is provided by vibrating the electronic component while the circuit board is fixed.
The vibration damping detect device in the bump joining determination apparatus may further include a vibration constituent current separator connected to the vibration generating device for relatively vibrating the electronic component and circuit board, for separating a vibration constituent current at the vibration generating device, and the deciding device determines whether the joining is good or defective on the basis of the vibration constituent current output from the vibration constituent current separator.
According to a second aspect of the present invention, there is provided a bump joining determination method for deciding whether a bump joining is good or defective at a time when electrodes of an electronic component and electrode parts of a circuit board are joined via bumps with the electronic component and circuit board relatively vibrated, the method comprising detecting damping in the vibration incident to a progress of the joining, and deciding the good or defective of the joining on a basis of the detected vibration damping.
A semiconductor component manufacturing apparatus according to a third aspect of the present invention is provided with the bump joining determination apparatus according to the first aspect.
According to a fourth aspect of the present invention, there is provided a semiconductor component manufacturing apparatus for joining electrodes of an electronic component and electrode parts of a circuit board via bumps with use of ultrasonic vibration so as to manufacture a semiconductor component, the apparatus comprising an impedance output device for making a vibration generating device generate the ultrasonic vibration and for sending an impedance related to the vibration generating device during the joining carried out via the bumps, and a joining determination apparatus for comparing changes in the sent impedance with an impedance of good joining when the electronic component and circuit board are joined well so as to determine whether the joining is good or defective.
The semiconductor component manufacturing apparatus according to the fourth aspect further comprises a pressure control device for making an electronic component hold member hold the electric component and move the electric component hold member in a thickness-direction of the circuit board, and for mounting the electric component onto the circuit board via the bumps while controlling a pressure, and a measuring device for measuring a shift of the electronic component hold member when pressing the electronic component onto the circuit board via the bumps at the pressure control device, so that the joining determination apparatus determines whether the joining is good or defective by further comparing changes in the shift of the electronic component hold member sent by the measuring device with a shift of good joining when the electronic component and circuit board are joined well.
Otherwise, the semiconductor component manufacturing apparatus according to the fourth aspect may be equipped with a pressure control device which makes an electronic component hold member hold the electronic component and moves the electronic component hold member in a thickness-direction of the circuit board so as to mount the electronic component onto the circuit board via the bumps while controlling a pressure, and which sends a pressing force of the electronic component hold member when pressing the electronic component onto the circuit board via the bumps, wherein the joining determination apparatus decides whether the joining is good or defective by further comparing changes in the pressing force of the electronic component hold member sent from the pressure control device with a pressing force of good joining when the electronic component and circuit board are joined well.
The pressure control device in the semiconductor component manufacturing apparatus of the fourth aspect may be adapted to send a pressing force of the electronic component hold member when pressing the electronic component onto the circuit board, the joining determination apparatus further deciding whether the joining is good or defective by comparing changes in the pressing force of the electronic component hold member sent from the pressure control device with a pressing force of good joining when the electronic component and circuit board are joined well.
In the semiconductor component manufacturing apparatus according to the fourth aspect, the joining determination apparatus can make the impedance output device change the ultrasonic vibration to improve a join state between the electronic component and circuit board when deciding the join state is defective during the joining.
In the fourth aspect of the semiconductor component manufacturing apparatus, the joining determination apparatus can make the impedance output device change the ultrasonic vibration to improve the join state between the electronic component and circuit board when deciding the join state is defective during the joining, and moreover, makes the pressure control device change the pressure to improve the join state if the join state is not improved simply by changing the ultrasonic vibration.
The semiconductor component manufacturing apparatus according to a fourth aspect further comprises a first memory for storing changes in the impedance sent from the impedance output device, shift of the electronic component hold member sent from the measuring device, and pressing force of the electronic component hold member sent from the pressure control device, and a second memory for storing changes in the impedance of good joining, the shift of good joining, and the pressing force of good joining, wherein the joining determination apparatus decides whether the joining is good or defective by comparing changes in the sent impedance with the impedance of good joining, shift of the electronic component hold member and shift of good joining, and pressing force of the electronic component hold member and pressing force of good joining stored in the first memory and the second memory respectively.
In the semiconductor component manufacturing apparatus according to the fourth aspect, the apparatus may further comprise a display device for displaying judgment results by the joining determination apparatus, and a third memory for storing a change in impedance when the joining determination apparatus determines that the electronic component and circuit board are joined defectively, wherein the joining determination apparatus makes the display device display the change in impedance when deciding that the electronic component and circuit board are joined defectively, and also makes the third memory store the change in impedance.
According to a fifth aspect of the present invention, there is provided a semiconductor component 25 manufacture method for manufacturing a semiconductor component by joining electrodes of an electronic component and electrode parts of a circuit board via bumps with use of ultrasonic vibration, the method comprising comparing a change in impedance related to generation of the ultrasonic vibration from a start to an end of joining between the electrodes and electrode parts with a change in impedance of good joining from the start to the end when the electronic component and circuit board are joined well, and deciding whether or not the joining is good based on the comparison.
In the semiconductor component manufacture method according to the fifth aspect, the method may further comprise applying the ultrasonic vibration, and moving and pressing the electronic component and circuit board to close each other via the bumps in a thickness-direction of the circuit board, in addition to the comparison of changes in the sent impedance with impedance of good joining, further executing at least one comparison of a change in shift between the electronic component and circuit board from the start to the end with a change in shift of good joining when the electronic component and circuit board are joined well from the start to the end, and a change in pressing force between the electronic component and circuit board from the start to the end with a change in pressing force of good joining from the start to the end when the electronic component and circuit board are joined well is conducted, and deciding whether or not the joining is good based on the comparison.
In the semiconductor component manufacture method according to the fifth aspect, the method may further comprises:
applying the ultrasonic vibration, and moving and pressing the electronic component and circuit board to close each other via the bumps in a thickness-direction of the circuit board;
in addition to the comparison of changes in the sent impedance with impedance of good joining, further executing at least one comparison of a change in shift between the electronic component and circuit board from the start to the end with a change in shift of good joining when the electronic component and circuit board are joined well from the start to the end, and a change in pressing force between the electronic component and circuit board from the start to the end with a change in pressing force of good joining from the start to the end when the electronic component and circuit board are joined well is conducted; and
deciding whether or not the joining is good based on the comparison.
Moreover, in the method of the fifth aspect, the ultrasonic vibration may be changed to improve a join state between the electronic component and circuit board when the join state is determined as defective during the joining.
Alternatively, according to the semiconductor component manufacture method in the fifth aspect, the pressing force between the electronic component and circuit board from the start to the end of joining when the electronic component and circuit board are moved in the thickness-direction of the circuit board via the bumps to be close to each other may be changed to improve the join state when the join state is not improved simply by changing the ultrasonic vibration.
In the constitution as above, according to the bump joining determination apparatus in the first aspect and the bump joining determination method in the second aspect of the present invention, the vibration damping detect device and deciding device are set to detect the vibration damping incident to the progress of the joining between the bumps and electrode parts or between the bumps and electrodes, thereby deciding based on the vibration damping whether or not the joining is good. The joining can be accordingly determined during the execution of the joining.
The semiconductor component manufacturing apparatus of the third aspect of the present invention features the bump joining determination apparatus and method of the above first and second aspects, so that the joining between the electronic component and circuit board can be determined while the joining is being carried out.
For the semiconductor component manufacturing apparatus in the fourth aspect and the semiconductor component manufacture method in the fifth aspect of the present invention are prepared the impedance output device, pressure control device, measuring device and joining determination apparatus are prepared, so that the ultrasonic impedance, downward shift and pressure of the electronic component hold member are measured in real time during the joining, whose waveform data are compared with waveform data of good joining, thus enabling detection of a defective join state.
Additionally, the display device for displaying judgment results and the third memory device for storing waveform data of defective joining are set. If the joining is determined as defective, the semiconductor component manufacturing apparatus is stopped, waveform data of the defective component is displayed by the display device, the defective component is removed and only good components are sent to a next process. Thus a join quality can be improved accordingly.
In the case where it is determined as defective during the joining by the joining determination apparatus, the joining determination apparatus monitors waveform data during the joining in real time, changes the voltage to be supplied to the impedance output device to change the ultrasonic vibration or changes the pressure value of the pressure control device, or changes both the voltage and the pressure value to change the join condition. Generation of defective components is thus prevented and a yield can be improved.